Dicarboxylic acid derivatives of lower alkyl ethers of vitamin b6, and a process of peparing the same



Patented Dec. 11, 1945 UNITED STATES PATENT OFFICE,

DICARBOXYLIC ACID DERIVATIVES OF LOWER ALKYL ETHERS OF VITAMIN Be,

AND SAME A PROCESS OF PREPARING THE John C. Keresztesy, Westfield, and Joseph R. Stevens, Plainfield, N. J., assignors to Merck & 00., Inc., Rahway, N. J., a corporation of New Jersey No Drawing. Application December 16, 1941,.

Serial No. 423,134

4 Claims.

with barium permanganate, and'recovering the said dicarboxylic acid derivative. The compounds have the formula COOH HOOC OR CHa N wherein R is a lower alkyl radical. Such derivatives can be used in the synthesis of vitamin B6,

Example 12.5 cc. of 0.1 molar barium permanganate is added, at first in small portions, finally in "larger amounts, to a solution of the methyl ether or vitamin Be (obtained by treating 105 mgms. of

'vitamin 3 base with a solution 01 diazo methane for example, as disclosed in our co-pending application Serial No. 247,479, filed December 23, 1938) in 5 cc. of water. The mixture is allowed to stand over night at room temperature, and the next morning the excess barium permanganate is decomposed by the addition of ethyl alcohol. The manganese dioxide is removed and well washed. The combined washings and the main filtrate are quantitatively ireed of barium ion by means of sulfuric acid. The barium sulfate (precipitate is removed, and the liquor is concentrated to a small volume. the dicarbomlic derivative oi the methyl ether of vitamin Be separating out in crystalline form. The crystals are recrystallized from water or water-acetone mixtures, and have a melting point of 2l3 215 C.

Analysis 0 H Calc.ior 0.11.0: 51.10 can Found. 51. 07 L 48 In a similar manner, dicarboxylic acid derivatives of ethers higher than the methyl ether may be obtained, for example of the ethyl ether, etc. Other modifications may be made in carrying out the present invention without departing from the spirit and scope thereof, and we are to be limited only by the appended claims.

We claim:

1. Th process comprising reacting a lower alkyl ether of vitamin Be with barium permanganate, and recovering the dlcarboxylic acid derivative of said lower ether.

2. The process comprising reacting an aqueous solution of the methyl ether of vitamin Be with barium permanganate, removing the barium ion, and recovering the dicarboxylic acid derivative of the methyl ether of vitamin B0.

3. The process comprising reacting an aqueous solution of th methylether of vitamin Ba with barium permanganate, treating the reaction mass with ethyl alcohol, removing the barium ion by means of sulfuric acid and recovering the dicarboxylic acid derivative of the methyl e her of vitamin Ba.

4. An oxidation product of a lower allgvl ether of vitamin B0, being further defined as containing two and not more than two carboxy groups and being of the chemical composition JOHN C. KERESZTESY. JOSEPH R. STEVENS. 

